SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeef76a69c546cb7f237bec4063d1a1f3cfdd39255c5956fd750b4f9a5c7a5f7' 
  AND token = 'a9yCvREDe0nIkz8tH4vDiOWecUQ2PkxNHv2qKC7+Pn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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