SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e270e873a39722dfe926f2d5af7d668331f24327561f8f5381364b7968a46bc3' 
  AND token = 'Bk+kJLF97c7bRQHror+V8NiAlAHEqxeZv9sZYqhO6go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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