SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa2042f987e294c30c4e49cdc37c405fa25f0016fceeddc5b539d29b6da3039d' 
  AND token = 'iWfRKVtBU2Lk9+wyYSlnMkQOapX7XNTAWfu3oMXXOQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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