SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebd494186a74951e3d775ee7b3f04ce0f2b1df671d039f4cb1cc2b59f68667ed' 
  AND token = '1SYtmJck2JniEdZEjDgTUG/KfzwdxoW3CzuGBlD0U3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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