SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cea71b533ce6c94dbb642c7247c457e48c67e300492283287c24f32b22f064f' 
  AND token = 'aBCWsfmSdAASqI/JBNhBQ70k6nM7HytkQRw2IPSQhiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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