SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64eda83a124ee76fc6208e7589fb624222dc27d006d3ba1db0993feb5562f4d1' 
  AND token = '5pqIK+omfEOOGZLXVbJWkFbBNGYcwtQF6WH+tHoUqSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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