SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6eed00730d3a6f0cab97bab2436dcaa896ef3f6cd5dd940ddf54ddbd7bfb4367' 
  AND token = 'Cf8767h7IXxnDUzoZKJyj8MyKzVzU9t4QQfBQNAZHPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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