SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daacecd9a2cca1646d12cfd202cdcbbf2f3521ed31043f05a5224f93b428282a' 
  AND token = 'jjYaOQi1Nj6/pHXcrA4vhFwJEdD4UU7PLTdUSShDgLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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