SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f194c20deeb16bd1ce1565a479d4308a32ff57753703d476d33d4e960b6d0637' 
  AND token = 's8kOUJP5Ur8/v6vD8Z0jvl+G+iE940YwJKYxxUQ2LNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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