SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9783300ba472e7aa74dcc22f94157e6059a940d35037477dccac88c7d984ee8' 
  AND token = 'XkuiaIjoNrqNvyyRxpKxi77pNwtEy8lKHEqJWVFXaNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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