SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9acb41a37fa325e256cbfd0566b8b78d4a414ee685a9a117d1a28852126dc95' 
  AND token = 'rZh93PGF3MjwhaQdQa0z+utsH8DypaRT8JidBGXIfnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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