SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c2df53cdfeb041e46e5d3263ed7b6adf49814975b27d69146b642563f001d67' 
  AND token = 'q/s1SbwIuSRqm/YUWoB08iNwaVNP8I+z0zZZkjBPpRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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