SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ca0ad25484651ab39b13ca7a3eba0d26673f9ebd9997d24501a3fc04257dd2b' 
  AND token = 'pMru36EjxLWHyPLu6yzr7ECV0QcgORmhs0x+JEyYqY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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