SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e129d67b5a36cbd10a2bb6a14075e5e60e229eb67f2ecdd805e7fe5c3546ce50' 
  AND token = '/qyfQ1CkqYqI8d3ugSEzL0JsnyUw+Hmh8zXZ+aDT9FE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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