SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec1a17d0427e0c49d91e9a040fc0be83630cc551f5857ae0b24cc5da244755f7' 
  AND token = '1bFUoHGYXka2wUDNMouinzdDpQ3E+ei5/lHZo3GgL2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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