SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '906a4601b45e882d9ae4175ee237d15ac36f9ff86bb3806fc99ad376728cff40' 
  AND token = 'HjWQIjUpbugEKWWeJlKsfX0Mt0H1m62ClCcnXgqc/Nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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