SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f5deeb5c5de22079014bcc61bce2eb736ed918992a78c6258bd13849b07402b' 
  AND token = 'H5pcQIt/o+M86Y+ilQRAHZZKE+zPEkNU+pGY3vzqhl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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