SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e642f6b4e76800fabf70f6048ce2a6a983ca4f38b390ade0014a333a0999efc2' 
  AND token = 'tCxXtq1cYoA6XXgEz93XSm7/GH7u+pavhlWqAHJVdfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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