SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa2992ee36ee07bfdfa82ca2689b445bbc2589a6f6c90b08560a2ccc3f700632' 
  AND token = 'V3k2qT3FJou+ocpyEKSWiXBMXtahx7ffCX6B8RNK3Aw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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