SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0e47cfb95b26436b1d30893bcdcbf2608020544e49ef3d961aabc92d61504f9' 
  AND token = 'bZRJOGQK/gj+q7JLCpE5YA62VzmmzqywoCbIAmfARCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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