SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6642a805144f63b1043bcd997792222576527346ef46cb0db6c409783b159ac' 
  AND token = 'Ko7xhbrEVxgrLfTzyYIv9mjKakDc5vS7UY2A0qd8G9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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