SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb13756d9a2680f78b022f426178ecf8be1fcd605a1e37223e0cc0a6dd718ab7' 
  AND token = 'u66E5fjjEeoHO0d43CjgvhgFKx/kctJaxPLIpxEMd/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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