SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86d23638abbd9bbc801e5568b752a5e711ac7386fb67a2709dd0959123a89420' 
  AND token = 'j7GRnK1RSSjC/qCaGU1EG0BALHoxrA/bvA6CdEAZues=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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