SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58ca6cae77453773dae92ace3ded95fededa831a6406660f56394a753ed3bf2b' 
  AND token = 'zrqmgN+ZUXPKszaV+TGJ2RN+UZej6VuP5W4sx2zCuBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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