SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86cb6e5247442b4d63b0b626b4247294f37f106815fdaa5e3f6c709198cc0087' 
  AND token = 'gKBICb0O/bl/uZ5ViApqL6K3pnxz0GfbOP4y07QUVaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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