SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83a0b04af3ad7e5ebf44f8d3282c9fb595946d2f9d6a71fd97ddc49242e80600' 
  AND token = 'hCGTKcDfAHA60jBGemiLuqD4cUYkjBkZ7KWYAcTZaaM=' 
  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"
    }
  }
}