SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0404f0fb4c368b816f311204cefa0945e06e63ee2490c7bf820f611cc9c70aac' 
  AND token = 'hFlgzwC9JpHWyYRKsROa25StoG/2gtU9kcGQ+aumLDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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