SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c08db7d249d9e40284af2dfa64d44809256a2aeee70410aaab24ddc2904a73b' 
  AND token = '1d1CMoAtutzNyPD/u2+PZRlwQYDFKK0HU3T0cdFXGaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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