SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ce4d1e8eb530dbeda621426e5905759075f50083968f0e22b141eca0b0103879' 
  AND token = 'fUOW2DZW/eHewaQDFKC3q5GmvoFilupjMnqdeFB1U2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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