SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ec825c76caa8997f947beecd96fb4fd2115f3e4719b03e6c3617603ef781968d' 
  AND token = 'xnSIb46VXIotKv23VAny8pBDAI+kdzVGii3BPRguLAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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