SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2912dc55affcaafe725ab5deda776952972be38247c8451cf4cb52819eb8536' 
  AND token = 'CdQKc3H6I+bQNUhVstFJpcan8wkWrS6tU3+t+v0k31g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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