SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12fc4517c14958d3d21b4c16211760939d0e04c6edae40445c2e3bca6634007a' 
  AND token = 'rIyLqFu6WHUBb8GyITAxnXnNindE8FViaFJb3eTfaOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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