SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94ca4cf37cd26a76fad68f6648e11ba1fe538a42f433e9d6f1c7bbb241ad47d7' 
  AND token = 'aT8rr9SIdl+RvTph3zizFzyDDRoUlL/ltMPKrfeso8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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