SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5788e774c2453a44e5c70d3f47e42306e4be0dd4570cc9cfa95e82ddfac5c75' 
  AND token = 'beIRuA6tiLWAANDc1HPg7kakazoCgCSZEJNl+RzR4ug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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