SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '31cb904ea2ef3aab96d2a6f2613d28ed6f7800441e668b46bc27345a1e2a0976' 
  AND token = 'B5+QLXO+iAwtVRrDKWk3zv9Mx7rue7GlhT3t09nBXwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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