SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a746a4c439afc316df3202787401ca72888697ca4c8fa70f9db3d0eefd8da8e' 
  AND token = 'ztVCK30/O82TIvg/tyePcAGoLDK/o6JPrwKeSiv4YZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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