SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bf438bf013af0ab5de9aa2e4af50524faa33c7ca1347e7736e3de06db9117c2' 
  AND token = 'UViZKXELu1m8D81oWWYqz6G/KSJLLcqk9epCZdTViXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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