SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8656dfdb02d0d74d90b58367ffd41cad81d3f089456c96f1740e91fb743f7914' 
  AND token = 'zFo4homP+RIxvZtYLgMdRaIL3Tlh5PAfiBM/ZwxeZgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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