SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1355460ff0f3fb155d30bf41e0b8e49799b38b61474c1ca92d6a378a5c554c46' 
  AND token = 'LHo9tgQqfqZi/J/ajYHFCQoJROoZM4r+G1MNy1Fkq+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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