SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79d629f2d703b8cc06996b79cbbc1d8d57bb2cc7c6a1a42a6b793b01538e56c3' 
  AND token = 'CLb2lIoLt3vlodbBETVJnSKCymSssyKLIXDPhXG3C1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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