SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e0055abf012d494963c4e0d2ce29351ba6125e7686c30ce75d9143af73c577e' 
  AND token = 'jqccDiOhyLPv7BdjXSMHmqZf/KXoa66QV1qtGoApwvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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