SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88ca5cf101d13836f1291fdebb261768a838bc26c03751b09c2fcf9196498cbe' 
  AND token = 'z1DHi4Xu4/SkbI7Wd0kmnxTrPI4++3C5UzyUaaUkprI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}