SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bd798ce8d462a21953294e5568c3097cdc94d75c704196a7c2004d879e36bc1' 
  AND token = 'x/KSaenXkICA9pjIxX78TUDBfwhbnpptfeQzzjVjinQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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