SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11c3467707e5351e4e5ef36ed600273b7313529bccfc5dd02a0b95b7c48dd3ca' 
  AND token = 'mYMOWrJRjuFY2VdC553119BGEv4DhoR6jVed6p0vzbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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