SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '690d378caabc2c46a01764d30e813b540ad369b2dfe29c0df9ab4f371e442238' 
  AND token = 'OhAjbsWJcFWRRhzHcF4oFWKsq1AqyAclEQhfRdhCpJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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