SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b51f1a8b63866d9d2e075f0c0286f2216ebab1599443d1404fe26303f45e9dc8' 
  AND token = 'Mbg0feTl/tw47a1gegh2NaEaHVlHwjc1yJgGjF3BKPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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