SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57e9633c2ecb0cbb5c9979f42038452dab971db81061dd776c345ac1c0903261' 
  AND token = 'sl6FhbeTfdaKCRFwuogtsIeMrPFfYgQIf5QYFTWT2/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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