SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1493a1cf84414a3dab47787434f3a3e41807345c382bad133d9c2bd6807c606b' 
  AND token = '5WyvVDfTTNN7+28V+liL9lKJjdkhBRFYUH3FzpuagDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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