SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b4cb1a9dd6f8a489d27e399e4626a58716965247728d15c155d3e1eeb92b000' 
  AND token = 'ILD03WmjOqcEOYtt7QqxpYOjwmBDrmHNH6PbQJWyE58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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