SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e394eee3dcfa4224184c9d17d67cfd7a75b162bd05ad2d5b4aeb941c56121b5' 
  AND token = 'qsQ6S8iTHKkwgga1n4lse+FjCGrLT2jjEHadhH7hWHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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