SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '438179360b38dda5c6fdfa459e4b9eba1099d50e0dd9ff796dfaf0877444d503' 
  AND token = '+3VZC/xp4u1KbFdFddX3Lgg9APvc0z3FikdswwgOlbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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