SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4156f654b0e1fe9d5ba7fab1d5e8f4348a11635f20f6887a519c173f54db1275' 
  AND token = 'Db2GQZSHeDTKZS3+uyTuSXgRcqyJLmE7ibLqQqfe2KI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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