SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ddd321909d2b183dd7b23fac5fd91dcbf1b0dcf7949e6d902e48d3d28d4f93e3' 
  AND token = 'n7xSXqbjkZ+njtpspyc/YN1S1TKYQclp2njvSMfpTa0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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