SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43268c32294c457c843fd713b1e164fd752254f53c5a902a74f80f9ea953c1de' 
  AND token = 'bNmJr+MZPdwMuUMsZvFYX3LuiBxbCJZhn3dBaajtTQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}