SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a0de6e0140e971f5a5e82ea2932dc736dd0d43034507d99b268192acd81fc5e' 
  AND token = 'U7yNRCWXaVQmK+sxc3iFqYGuYGNeXrHNJetlTf6WOko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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