SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f653d1548714762c24b608bd6dc7a7513fa13bcfdcee7a93c1ddc22226797bd' 
  AND token = 'MtT+E3UI09wE4Nu4zpZmjYxqxFXvuAHlUQ58reTlolg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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