SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a265179f887c84da3a78186941d525fb8c78c6e9e362fe319e51fadaabb698c9' 
  AND token = 'UbVKXa7QLAdyJGvKOCCLY/+utVSPX7fNQ/Fw291IyfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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