SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7285642dd98670fe80086a7c8e78a29bac3635f4e59d2d70d8054a0fd6db2ac' 
  AND token = 'jUgLWKLH1rNE2RLWpuLkhn6fV9FJYBd/URlSGcBwi2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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