SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f296236e10da1f4d0f8339b5bd51985e5c99130f4276808667099a2c37eabee' 
  AND token = 'OChYNnWnqAUq88EDl+VuW9Dmi/vESxoJaWALpRWDKfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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