SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2d4531613ccffa66450c1b7dd9d18b53028847ecfbcc69505e03776ba30d051' 
  AND token = 'VKyCafTAH3rfjnAGtlk3cS4u9gzHgaf1+ALoiTXpNRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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