SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17a99ccc8c532b2903d03c4633262f1636e260beb3d372a1025e17d9c79b505c' 
  AND token = 'dQomxXeM+GC6OQpftg8XjQnQ80iF+dD0Ip0XnG+mjE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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