SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c52ae1348b2c20d392769e2a24bfd228751ad6a94b4b291e106a1e63aaf12ea9' 
  AND token = 'ilkD288ppsceJ00uG4bRgwLKprzbtGpRKfK7aqJHmUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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