SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '711cdf960fcde1479ea76d1fb0a8a7679cb57ff61dd76cfcb51d0b65a1eaa438' 
  AND token = 'wQCS4dWcwuQ5KZ/8so2/MbA+NgHNp4WilPoAB0+LIsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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