SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f2ee2936684b8ef575a3d6c982d10cefd2f9f28b0faa6922732c7d7fa13445c2' 
  AND token = 'pqCCtx3RiRBRYrWKOv+ZlHV5Y6dKKGqscASCZUQv6bg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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