SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1d892070e2f444452a568224ee37338e92e23dd909520ded3a685a12a688b1d' 
  AND token = 'y3Yf1i21jzS1cWk2eWwwBKKEticR7DH6tcRiWbD90BA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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