SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c06a48e8fac4ec95281ab1442575966117f3d5593e11f96761fe26be32a4082a' 
  AND token = 'QF46PiPnJIiQWfFPaeg4GhIdYpELvUWEdhhxWRLcAFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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