SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '56322aca450f0025840d8ee7c20312a2b9ba7d265943409315ea8c2e6c8b4378' 
  AND token = 'qC0QlwCLBAGp/BXujobGK+f/mlFz60jI1dp9pnemW5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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