SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fde5cca1723fafb505755ab1ba2f0f5d1ca3ec3dbd8878d7d44e333035304d40' 
  AND token = 'GRpEc+AG+wROKKX4tgDhAzgFJhkuQ8PW/RggKGLwBEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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