SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc29b58e4413b110aafb0e302522fa74e6379e7e255d376b8ce41df8b5c5a7ca' 
  AND token = 'jvfdWOytIiYzAiVV8stgc7Z7WavvwolgDol/nL66SBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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