SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '114346bdb8fb5fc59383746d35f337e70dc84a6d2beee12fe103defb2f897bd3' 
  AND token = 'tABISPImAk6zcCVmOOyiZzyF12MY/R/vxcz0H7TX9qM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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