SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '114b049ce47029ff0515fa58fb14c1bdfcc91d94ef212f750d5c6d1739ef00ed' 
  AND token = 'REOnpStLgTLit40g3UQuAklRNN2NTLsYLVf7mDnIHfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}