SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7143331ab20ffb1086e6434fd6098eb9713536a268d5361a9ece8693bc1b686a' 
  AND token = 'RThJLiglqTsJCjhnEUG9e6h+zAIvWnGDDuvJpifiDeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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