SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c256418741fb784c2088e69a7aad3fd7a41c595eefe710dcc8f6e8202d50569b' 
  AND token = 'JHVZ+R2RBR17LBYSsYXdB3hQOQYgUJfPNPxZeDurQFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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