SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80b444ba26a321c025c77c3259efa468d9f3b703d965d54958abdb4326416422' 
  AND token = '/FDXFaVw/8WNMMxwqmvdAsAlirz6YQkw1JLNJkZtfoQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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